The overall goal of this project is to expand on the evaluation of an ongoing NIH grant "Improving Safety and Access for Physical Activity" (Positive Action for Today's Health (PATH): R01 DK067615). Specifically this supplemental project will add trail observations and spatial analyses to enhance our understanding of how the PATH interventions may work. Two communities in the PATH trial have been randomized to receive a social marketing plus police patrolled-walking program or a police patrolled walking only intervention. We have developed protocols for conducting systematic trail use observations and audits of the physical trail-related environment and have developed additional individual level measures of related social environmental factors (community connectedness, collective efficacy, social networks, social support) for this supplemental project. Internal bridge funds have been provided by the South Carolina Research Nutrition Consortium to allow us to conduct baseline assessments of these measures prior to beginning the PATH interventions. This proposed supplement project would support the 12-month, 18-month and 24-month trail observations which will provide a second primary outcome for PATH as well as enhance our understanding of how the social marketing intervention is related to improvements in social factors, moderate physical activity (MPA) and trail use over the 24-month intervention. A total of 260 (130 per community) participants will be the focus of this supplement grant (219 recruited to date). The primary aims of the supplemental project will be to examine 1) trail use in the social marketing plus police patrolled walking vs. police patrolled-walking only communities, 2) how, household proximity to the walking trails and residential clustering of trail use are associated with individual level social environmental variables, and 3) how changes in MPA and trail use are mediated by improvements in individual level social factors in social marketing intervention participants from baseline to 12-months, 18-months and 24-months. PUBLIC HEALTH RELEVANCE: The benefits of the proposed research will include increasing our understanding about how social marketing, proximity to the walking trails, and clustering of higher trail use in certain residential areas relates to changes in the social and physical environmental eterminants of physical activity and trail use in low-income, high violent communities. Understanding the social and physical environmental mechanisms in promoting physical activity in underserved communities will ultimately reduce the rate of obesity, chronic disease, and health care costs in the United States.